Clutch mechanism



Oct, 24, 1961 R. E. ECKMAN CLUTCH MECHANISM 2 Sheets-Sheet 1 Filed Sept. 8, 1958 Q &

INVENTOR A. E. Eek/nan R. E. ECKMAN LUTCH MEC Oct. 24, 1961 HANISM 2 Sheets-Sheet 2 Filed Sept. 8, 1958 ATTORNEY Patented Oct. 24, 1961 Texas Filed Sept. 8, 1958, Ser. No. 759,616 12 Claims. (Cl. 64-29) This invention relates broadly to improvements in clutches generally, but more particularly to clutch devices adapted for use in portable power driven tools such as used for setting screws, nuts, bolts and the like.

One object of this invention is to produce a simple and efiicient releasable torque responsive clutch capable of maintaining a uniform torque under different conditions of operations.

Another object of this invention is to produce a releasable torque responsive clutch mechanism incorporating simple and dependable means for adjusting, within a relatively large range, the maximum torque to be transmitted through the clutch.

Other objects and advantages more or less ancillary to the foregoing reside in the specific construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification.

In the drawings:

FIG. 1 is a side elevational view, partly in section and with some of the parts omitted, of a portable tool embodying the invention.

FIG. 2 is an enlarged view of a portion of FIG. 1, illustrating some of the parts in operative positions.

FIG. 3 is a View similar to FIG. 2, illustrating the same parts in inoperative positions.

FIG. 4 is an enlarged cross sectional view taken on line 44 in FIG. 1 and looking in the direction of the arrows.

FIG. 5 is an enlarged view of a portion of FIG. 4 but showing the parts in a different position.

FIG. 6 is an enlarged cross sectional view taken on line 6-6 in FIG. 1 and looking in the direction of the arrows.

Referring to the drawings in which like symbols designate corresponding parts throughout the several views, 10 designates the front end of a fluid rotary motor well known in this art, which motor is generally provided with a back head 9 having motive fluid admitted thereto through a conduit 8 and controlled by a throttle valve 7 actuated by a trigger 6. Since the motor forms no part of this invention, no further showing and description is necessary, other than pointing out that such motor has an output shaft, the front end 11 of which is shown journalled within a ball bearing 12.

To the front end of the motor 10 is screwed a front housing '13 which extends axially therefrom and is adequately machined to accommodate within its front end a .slidable work guide piece 14 rotationally fixed to the housing by a key 15. This key extends through a radial hole 16 provided through the housing and is carried by a removable split ring 17. In order to limit the forward movement of the guide piece, the key is engageable with the inner end of its key slot 18 provided in the guide piece, which guide piece is urged forwardly by a compression spring 19. The guide piece has its front end internally shaped to fit over the work, such as a screw not shown, and guide the forward end of the tool implement 22 into operative engagement with the work. The rear end portion of the tool implement is provided with an hexagonal shank 23 detachably mounted within a corresponding bore 24 provided within the front shafted end portion or socket 25 of a sleeve or spindle 26. The

shank 23 is detachably locked to the spindle 26 by the usual spring detent 27 fitting within an annular recess other or inner end of the spindle 26 is enlarged to form a head 29 provided with a smooth central bore 30 closely fitted for running fit over the shank portion 31 of a driven clutch member 32. This clutch member hasa flange 33 having one side bearing against the inner end of the spindle 26 and its other side provided with radially extending jaws 34. The jaws 34 are capable of operative engagement with corresponding jaws 35 provided on the front face of a driving clutch member 36 which is fixed to the output shaft 11 by any suitable means such as a lock member 37. The spindle 26 and clutch member 32 are maintained in coaxial alignment by a rod 38 which extends through the clutch member 32 withone end extending into the rear end portion of the spindle 26 and the other end into the front end of the motor shaft 11, while the front end portion of the spindle bears within the casing 13 as at 39. Within the output shaft 11 the rod 38 is backed by a compression spring 40, the function of which will be explained later.

The front end portion of the shank 31 of the driven clutch member 32 within the bore 30 of the spindle 2 6 is provided with a polygonal cam portion 41, which in this instance is shown to be of the hexagonal type, with 44 extending radially through the head 29 of the spindle 26. Each detent is urged against the cam by an L- shaped detent retaining dog 45 having a first'arm 46 substantially parallel to the center axis of the spindle 26 with one end engaging the detent while its other end is integrally joined to a second arm 47 substantially perpendicular to that axis. :Below its head 29 the spindle 26 is provided with an external annular recess 48 into which the arms 47 are located. This recess is provided with an annular step 49 having its inner wall engageable by a relatively sharp edge 50 raised on the arm 47, which edge cooperates with the step 49 to form a pivotal mount for the dog 45 on the spindle 26. Each arm 46 is located within a shallow groove 51 of a width substantially equal to that of the arm 46, which groove extends longitudinally on the spindle head 29 from the recess 48 to the detent bore 44. Thus fitted in the grooves 51, the dogs 45 rotate with the spindle 26.

A compression spring 52 surrounds the spindle 26, with one end engaging a spring follower 53 axially movable but rotationally locked to the spindle by a key 54 fitted within a key slot 55. The follower 53 can be adjusted axially by an adjustment nut 56 screwed on the spindle. The other end of the spring engages another spring follower 57 which bears against the arms 47 of the detent retaining dogs 45 as clearly shown in FIGS. 2 and 3.

During operation, as the guide piece 14 is applied on the work and axial pressure is exerted by the operator on the handle 9, the entire tool together with the tool implement 22 moves forward relative to the guide piece 14. As the tool implement engages the work, and upon continued pressure by the operator on the handle 9, the inner end of the tool implement 22 which engages the corresponding end of the socket 24 will drive the spindle 2'6 and driven clutch member 32 toward the driving detents 43' with the sides of the cam 41, which engagement is normally maintained by the force of the spring 52 acting on the dogs 45 to impart a pivotal thrust on the arms 46 against the detents 43, and the consequential radial thrust of the detents against the sides of the cam. It will be noticed that the action of the spring 52' through the follower 57 on the arms 47, is outside the pivotal mounts between the dogs 45 and the spindle relative to the center axis of the spindle, thereby resulting in the pivotal thrust of the arms 46 against the detents 43.

When the work or screw is set, further rotation of the tool implement 2'2 and spindle 26 is prevented even though the clutch 3236 is still engaged. That is, upon a predetermined resistance to rotation of the spindle 26, as the corners of the cam 41 pass under the detents 43 as shown in FIG 5, the cam will drive the detents outwardly against the thrust of the dog arms 46 by further compressing the spring 52, thereby efiecting slippage of the clutch between the spindle 26 and clutch member 32 as long as the operator exerts pressure on the handle 9. The maximum torque to be delivered by the tool can be varied by adjusting the nut 56 on the spindle 26 to increase or decrease the compression of the spring 52.

As the tool is removed from the Work, the spring 40 acting on the rod 38 will drive the spindle 26 and clutch member 32 forwardly to eliect disengagement of the clutch 32-36, while the pivotal thrust of the dog arms 46 will drive the detents 43 in engagement with the sides of the cam 41 as shown in FIG. 4.

Although the foregoing description is necessarily of a detailed character in order to completely set forth the invention, it is tobe understood that the specific terminology is not intended to be restrictive or confining, and it is to be further understood that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as claimed.

I claim: I

1. In a device of the character described, a pair of coaxially disposed members, rotation transmitting means between said members including a cam on one of said members, a radially movable detent on the other member' engagingsaid cam, a dog mounted on one of the said members and arranged to pivot on an axis transverse to the axis of the said member, a single spring biasing said dog to maintain said detent in engagement with said cam to normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of one of said members adapted to drive said detent to deflect said dog and enable relative rotation between said members.

2. In a device of the character described, a first and a second coaxially disposed members, rotation transmitting means between said members including a cam on said first member, a radially movable detent on said second member engaging said earn, a dog pivotally mounted on said second member and arranged to move in a plane which includes the axis of said second member, a single resilient means urging said dog in a direction to maintain said detent in engagement with said cam to normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of said second member adapted to drive said detent to deflect said dog and enable relative rotation between said members.

3. In a device of the character described, a first and a second coaxially disposed members, rotation transmitting means between said members including a cam on said first member, a radially movable detent on said second member engaging. said cam, a dog pivotally mounted on said second member and arranged to move in a plane which includes the axis of said second member and to maintain said detent against said cam, a single compression spring acting on said dog to normally prevent it's pivotal movement and the relative rotation between said members, said cam upon; a predetermined resistance to rotation of said second member adapted to drive said detent to pivot said dog and enable relative rotation between said members.

4. In a device of the character described, a first and a second coaxially disposed members, rotation transmitting means between said members including a cam on said first member, a radially movable detent on said second member engaging said cam, an L-shaped dog pivotally mounted on said second member and arranged to move in a plane which includes the axis of said second member with one arm maintaining said detent againstv said cam, a single compression spring acting on the second arm of said dogv to normally prevent pivotal movement of said first arm away from said cam and prevent relative rotation between said members, said carrr upon a predetermined resistance to rotation of said second member adapted to drive said detent to pivot said one arm and enable relative rotation between said members.

5. In a device of the character described, a pair of coaxially disposed members, rotation transmitting means between said members including a regular polygon cam on one of said members, a radially movable detent on the other member engaging one side of said cam, a dog pivotally mounted on one of said members and arranged to move in a plane which includes the axis of said second member, a single resilient means urging said dog in a direction to maintain said detent in engagement with said one side to normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of one of said members adapted to drive said detent to deflect said dog and enable relative rotation between said members,

6'. In a device of the character described, a pair of coaxially disposed members, rotation transmitting means between said members including a regular polygon cam on one of said members, a radially movable detent on the other member engaging one side of said cam, a dog pivotally mounted on one of said members and arranged to move in a plane which includes the axis of the said member to maintain said detent against said one side, a single compression spring acting on said dog to normally prevent its pivotal movement and the relative rotation between said members, said cam upon a predetermined resistance to rotation of one of said members adapted to drive said detent to pivot said dog and enable relative rotation between said members.

7. In a device of the character described, a first and a second coaxially disposed members, rotation transmitting means between said members including a regular polygon cam on said first member, radially movable detents on said second member engaging the said cam, detent retaining dogs having pivot mounts on said second member, said dogs having the greater portion thereof disposed substantially parallel to the center axis of said second member, a single compression spring acting on said dogs outside of said pivot mounts relative to the center axis of said second member causing said dogs to thrust said detents against said cam and normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of said second member adapted to drive said detents to pivot said dog against said compression spring and enable relative rotation between said members.

8. In a device of the character described, a first and a second coaxially disposed members, rotation transmitting means between said members including a regular polygon cam on said first member, radially movable detents on said second member engaging said cam, detent retaining dogs carried by said second member for rotation therewith and having pivot mounts on said second member, said dogs having the greater portion thereof disposed substantially parallel to the center axis of said 75, second member, a single compression spring acting on said dogs outside of said pivot mounts relative to the center axis of said second member causing said dogs to thrust said detents radially inward against said cam and normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of said second member adapted to drive said detents radially outward to pivot said dogs against said compression spring and enable relative rotation between said members.

9. In a device of the character described, a first and a second coaxially disposed members, rotation transmitting means between said members including a regular polygon cam on said first member, a radially movable detent on said second member engaging one side of said cam, a detent retaining dog on said second member having a first arm substantially parallel to the center axis of said second member in engagement with said detent and a second arm substantially perpendicular to said axis having a pivot mount on said second member, a compression spring acting on said dog outside of said pivot mount relative to said axis causing said first arm to thrust said detent radially inward against said side of said cam and normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of said second member adapted to drive said detent radially outward to pivot said dog against said compression spring and enable relative rotation between said members.

10. In a device of the character described, a first and second coaxially disposed members one surrounding the other, rotation transmitting means between said members including a regular polygon cam on said first member, a radially movable detent on said second member normally engaging one side of said cam, a detent retaining dog on said second member having a first arm substantially parallel to the center axis of said members in engagement with said detent and a second arm substantially perpendicular to said axis having a pivot mount on said second member, spring means acting on said second arm outside of said pivot mount relative to said axis imparting a pivotal thrust to said first arm and a radial thrust to said detent against said side of said cam to normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of said second member adapted to drive said detent against said first arm to pivot said dog against said spring means and enable relative rotation between said members.

11. In a device of the character described, a first member, a second member within said first member coaxial- 1y therewith, rotation transmitting means between said members including a regular polygon cam on said second member, a radially movable detent on said first member normally engaging one side of said cam, a detent retaining dog on said first member having a first arm substantially parallel to the center axis of said members in engagement with said detent and a second arm substantially perpendicular to said axis having a pivot mount on said first member between said first arm and center axis, spring means acting on said second arm outside of said pivot mount relative to said axis imparting a pivotal thrust to said first arm toward said axis and a radial thrust to said detent against said side of said cam to normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of one of said members adapted to impart a radial thrust to said detent and a pivotal thrust to said first arm away from said axis to enable relative rotation between said members.

12. In a device of the character described, a first member, a second member within said first member coaxially therewith, rotation transmitting means between said members including a regular polygon cam on said second member, a radially movable detent on said first member normally engaging one side of said cam, a detent retaining dog carried by said first member for rotation therewith having a first arm substantially parallel to the center axis of said members in engagement with said detent and a second arm substantially perpendicular to said axis, a recess within said first member, a pivot mount for said second arm within said recess, a compression spring surrounding said first member acting on said second arm outside of said pivot mount relative to said axis imparting a pivotal thrust to said first arm toward said axis and a radial thrust to said detent against said side of said cam to normally prevent relative rotation between said members, said cam upon a predetermined resistance to rotation of one of said members adapted to impart a radial thrust to said detent and a pivotal thrust to said first arm away from said axis to enable relative rotation between said members.

References Cited in the file of this patent UNITED STATES PATENTS 852,045 Vivinus Apr. 30, 1907 1,953,430 Parre Apr. 3, 1934 2,207,038 Trier et a1. July 9, 1940 2,263,709 Van Sittert Nov. 25, 1941 2,514,227 Dodge July 4, 1950 

